Verticaltubular boiler



UNITED STATES PATENT OFFICE.

vTHOMAS L. STURTEVANT AND THOMAS J. STURTVANT, OF FRAMINGHAM,

A MASSACHUSETTS.'

VERTICAL TUBULAR BOILER.

SPECIFICATION forming part of Letters Patent No. 487,794, dated December 13, 1892.

Application tiled .l'uly l1, 1892. Serial No. 439,646. (No model.)

To all whom, t may concern.-

Beit known that we, THOMAS LSTURTEVANT and THOMAS J. STURTEVANT, citizens ot the United States, residing at Framingham, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Vertical Tubular Boilers; and we do hereby declare the following to be a full, clear, and exact description of the invention, .such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to figures of reference marked thereon, which form a part of this specification.

This invention relates to improvements in vertical tubular boilers, particularly that class in which a single grate and combustion-chamber are employed in connection with two generators, one partially inclosed by the other, and so arranged that they may make steam independently, or may be allowed to act conjoint-ly as a single steam-generating apparatus.

This invention further relates to that type of boiler called vertical submerged liucbo ilers,7 and may be considered as an improvement on that shown and described under application Serial No. 432,264, filed jointly by us onv May 9, 1892.

The peculiar features in the present instance consist in the combination of two steam generators, the larger one being, preferably,

' circular and containing the lues arranged in an annular group, while the smaller extends vertically therethrough and projects down into the iire-chamber common to both.

The invention relates, moreover, to the steam-dome which surmounts the larger generator. Thus the heating-surface is increased and the water capacity is reduced, thereby diminishing the Weight of theboiler, but enabling steam to be created more rapidly'from cold water, while the highsteam chamber prevents the liability to prime.

Other advantages of construction will be hereinafter explained and described.

In the drawings, Figure 1 is a front elevation of acompound boiler embodying our invention. Fig. 2 is a vertical section. Fig. 3 is a horizontal cross-section on line y 'yof one.- half of av boiler.

tion. lchamber at 8, while a series of tubes or [lues In the drawings, 2 represents our submerged vertical tubular generator, composed of an exterior shell 3, an upper tube-plate 4, preferably of annular shape, and a crown-sheetI 5, provided with a concave or retreating cylindrical portion 6. In general shape this generator is of inverted-U shape in vertical sec- The stack is shown at 7, and a lire- 20 connect the top and bottom plates 4 5 and provide for the escape of the products of combustion from the fire-chamber into the stack. In connection with this tubular generatonwe have provided a secondary generator 9, which extends centrally of the main one, but projects both above and below the latter. At the top this secondary generator is inclosed by a steam-drum 10, which surmounts the central portion of the main generator not supplied with tubes, while below it extends into the tire-chamber. This secondary generator 1s arranged to operate independently of or conjointly with the primary generator by means of the valve 12 and plug 13, as will be hereinafter explained. The lowermost part of said generator serves as a mud-drum.

To increase the size of the lire-chamber and likewise the heating surface and power ofthe boiler, we have formed an annular projecting water-leg 14, which extends below the generator 2 and forms the walls of said chamber. The angle of this oiset water-legis such that it directs and causes the rising water to sweep across the tube-plate and tubes, thereby 1ncreasing the circulation.

angle,would accomplish the same purpose, A feed-pipe 15 supplies this generator with fresh water, while a blow-off is provided at 16. The central or small generator is primarily 1ntended for salt-water and has feed and blow- 0E pipes, respectively, at 17 18. A plug 19 enables the pipe leadingthereto to be cleansed, if necessary. Independent water-gages, trycocks, and steam-gages are supplied in the rately.

In the operation of this boiler, We will instance that the generator 2 is supplied with fresh water and that generator 9 contains saltwater. Under these conditions plug 13 is in It is evident that .a plate or partition 21, taking the place of thisv Vevent of the two generators being used sepa- Y IOO place and valve 12 is open, in this way per vfore flowing into the incre-complicated and net -so-easily-cleaned generator. From the plaln surfaces otl the generator 9 scale and sediment are easily removed. serves as the steam-pipe for the boiler proper, while the pipe 19 performs the same service 1n case the generator 9 is usedindependently.

`What we claim is- I 1. The combination, with a generator hav- 1ng an -annular group of vertical tubes, of a steam-dome surmonnting that portion not supplied with tubes and an inclosed central generator adapted to extend Within said dome and project below the tubular generator, sub- Stantially as specied.

2. In combination, with a vertical tubular generator and its annular offset Water-leg, of the steam-dome which surrounds said generator` and the generator 9 inclosed by the rst and adapted to project into the re-cha1nber The pipe 18" below and into the steam-dome above, substantially as stated.

3. In a steam-boiler, the combination, with a group of vertical fines, an inclosed central generator, and a steam-dome which surmounts said generator, as described, of a crown-plate provided with a retreating cylindrical portion, whereby the heating-surface of both the inner and outer generators is increased, substantially as and for purposes explained.

4. Avertical tubular boiler consisting of a generator with a group of flues adapted to unite the stack with the tire-chamber, a central inclosed generator, an offset water-leg which surrounds said firefchamber, a steamdome surmonnting said generator, and a crown-sheet formed with a concave portion serving as the inside Wall and bottom of said water-leg, all substantially as shown and described.

In testimony whereof we affix our signatures in presence of two witnesses.

THOS. L. STURTEVANT. THOMAS J. STURTEVANT.

Vitnesses:

H. E. LODGE, FRANCIS C. STANwooD. 

